Winch



M. B. BENSON Nov. 7. 1939.

WINCH 3 Sheets-Sheet 1 Filed June 12, 1937 |NV ENTOR M. B BENSON Nov. 7, 19 39.

WINCH Filed June 12, 1937 3 Sheets-Sheet 2 rill/1:5

INVENTOR power shaft 24 driven by an electric In operation, only one of thegypsiesor only.

' one of the drums can be operated at a time. The

be operated is se-.

Patented Nov. 7, 1939 I New York, N.

Y., assignor to Lidgerwood Manufacturing Company, Elizabath, N. J., a corporation of New York Application June 12, 1937, Serial No. 147,857 12 Claims. (Cl. 254-185) My invention relates to improvements in winches of the general type such as are used aboard ship for towing and mine sweeping, and cargo handling.

One of the objects of my invention vision of an improved construction for winches the way of greater 'ease and safety of operation,

compactness, lighter weight for a greater ease of emciency.

Other objects appear.

For the purpose of illustrating my invention, several embodiments thereof are shown in the drawings, in which Figure 1 is a simplified, plan view, partly diagrammatic and partly in section, of a towing and mine sweeping winch constructed and operating in accordance with my invention, the section being taken on the parts being has;

Figs. 2 and 3 are enlarged, fragmentary, sectional views, the sections being taken on the lines -2 and 33, respectively, in Fig. 1;

Fig. 4 is an enlarged, fragmentary view, partly in section, taken from Fig. 1;

- Fig. 5 is an enlarged sectional view, the section being taken on the line 55 ii? Fig. 1; I

Fig. 6 is a simplified, end, elevational view, looking toward the right in Fig. 1;

' Fig, 7 is an' enlarged, detail, sectional view, the section being taken on the line 1-1 in Fig. 1;

given capacity, making adjustments, and higher andadvantages will hereinafter removed for the sake of clear- Fig. 8 is asimplified, elevationai. view, partly diagrammatic and partlyin section, of a cargo winch constructed and operating in accordance with my invention, the section being: taken on the line 8-8 in Fig. 9, some of the parts being removed for the sake of clearness; and

-- Fig. 9 is a simplified,.end elevationaiview,

looking toward the left in Fig. 8.

With reference to Figs. 1 to -7, the reference 7 numerals I and -II designate input shafts supported in alignment by bearings l2, l3, l4 "and i for rotation about a common axis and independently of each other. A gypsy i6 and two drums l7 and iii are driven-by means of planetary gearing i9 fromthe input shaft l0, and a drum and a gypsy 2! are driven by means of planetary gearing 22 from input shafts l0 and by means of planetary gearing 23 motor 25.

particular gypsy or to. I lected by turning the handle23ofa single, fluidpressure valve 21 to definite "positions A, B, N;

the line l-l in Fig. 2, some of ,the input shaft II'.. The ii are selectively connected toa single is the pro- 4 The planet gears 3| -34 and 35. A brake plied, the input power shaft 24,

- compressed air ill and II and tin.

. 53 fixed on the input shaft iii, a ring gear 54 C and D, the valve being shown in position N, after which the master controller 28 of the motor is actuated to cause rotation of the selected from the power shaft 24, aring gear 30, planet gears 3|. The ring gear 30 is on the inside of a brake drum 32 forming part of a casing 33 having hollow stud shafts 34' and 35 which are journailed, respectively, in bearings-36 and 31. are carried by aspider 38 having hollow stud shafts 39 and 40' which are journalled, respectively, in the hollow stud shafts drum 4| is fixed on the hollow shaft 40 which is also journalled in a bearing 42. The driving connection between the planetary gearing 23 and the input shaft' l0 comprises a chain 43 connecting a gear 43a fixed on the shaft l0 and a gear 44 fixed on the hollow-shaft 35. K The driving connection between the planetary gearing23 and the inputshaft ii comprises a chain 45 connecting a gear 46 fixed on the shaft II and a gear 41 fixed on the hollow shaft 40.

The drum 32 is held against rotation or released by a friction brake'band 48 of a conventional construction and which is applied by a spring 49 and released upon the supply of compressed air to a cylinder 50. The drum. is' held against rotation or released by a similar friction brake band 5! applied by a spring and released upon the supply of compressed air to a cylinder 52. That is, both brakes arespringapplied and air-released, and it will be seen that with the brake 43 released and the brake 5| apshaft in will be driven from the and with the brake 48 applied and the brake 5| released, the input shaft -ll will be drivenfrom the power shaft. Also, with the shut off from bothcylinders 50 .and 52, and these cylinders vented, both brakes will be appliedby the spring pressure to hold the respective drums 32 and 4| against rotation, and accordingly hold or lock both input shafts the power shaft 24 against rota- The-planetary gearing l9 comprises a sun gear fixed on the inside of the drum I8, and planet gears 55 carried by a spider 56 in which the shaft I8 is journalled. The spider 56 is provided on one side thereof with a hollow shaft 51 journalled in the hub 58 of the drum I8, the hub-58 being journalled in the bearing I3. The hub I8a of the drum I8 is journalledin the bearing I I, as shown.

The drum I1 is loosely mounted on the hollow shaft 51, and a clutch collar 59 provided with pins 68 is splined on this shaft. With the collar 59 in the righthand position shown, the pins 68 engage either the gypsy I6 or .position, the pins 'the drum I8 and a partition 13 in holes in the adjacent face of the'drum I1 to to the shaft 51 for rotation the collar 59 in the lefthand 68 engage in holes 62 in the adjacent flange of a sleeve 63 journalled in the bearing I2 and on which the gypsy I6 is fixed. In this way, the gypsy I6 is coupled to the shaft 51 for rotation therewith. As shown in Fig. 4, the collar 59 is moved by a yoke 64 pivotally mounted at 65 and connected in any suitable manner to couple the latter therewith. With an air cylinder 66. A compressed spring 66a in the righthand end of the cylinder 66 operates to hold the collar 59 in the righthand position when the pressures in opposite ends of the cylinder are equal. In the particular arrangement shown, it will be seen that upon the supply of compressed air to the righthand end of the cylinder 66, the collar 59 will be held in the righthand position by air pressure as well as by the pressure of the spring 66m, and the drum 11 will accordingly be selected for rotation with the shaft 51, and that upon the supply of compressed air to the lefthand end of this cylinder, the collar 59 will be moved to the left against the action of the spring 660 tc select the gypsy I6 for rotation with the shaft 5 The drum I8 is provided with a brake drum 61 which is released or held against rotation by a friction brake band 68 which, like the brake bands 48 and 5I, is applied by a spring to hold the drum I8 against rotation'and is released upon the supply of compressed air to an air cylinder 69.

The drum I1 is providedwith a brake drum 18 which is released or held against rotation by a friction brake band 1! which, like the brake bands 48, SI and 68, is applied by a spring 18a to hold the drum I1 against rotation and is released upon the supply of compressed air to an air cylinder 12.

From the foregoing, it will be seen that with the brake 68 released and the brake 1I applied, only the drum I8will be driven from the input shaft I8 through the planetarygearing, because the planet gears 55 are now held against bodily rotation by the interlocking engagement of the collar 59 with the fixed drum I1. With the brake 68 applied and the brake 1I released, the ring gear 54 will be fixed and the hollow shaft 51 will rotate with the planet gears. In this case, the drum' I1 will be driven from the input shaft I8 through the planetary gearing, depending upon the position of the clutch collar 59.

The planetary gearing runs in oil which is con fined in the space between the adjacent face'of through which the input shaft I8 passes with a loose fit.

The planetary gearing 22 comprises a sun gear 14 fixed-on the input shaft II, aring gear 15 fixed on the insideof the drum 28, and planet gears 16 carried by a spider 11. The spider 11 is provided with a hollow shaft 18 journalled in the bearing I5 and on which the gypsy 2| is fixed. The adjacent end of the input shaft II extends into and is journalled in the hollow shaft 18, as shown. The planetary gearing runs in oil which is confined within the drum 28. As shown in Fig. 5, the drum 28 has a bearing on the hollow shaft 18 and on the input shaft II.

The drum 28 and they gypsy 2I are provided, respectively, with brake drums 19 and 88 which are released or held against rotation by friction brake bands 8I and 82, respectively. The brake bands 8| and 82, like the others, are applied by springs and released upon the supply of compressed air to the air cylinders 83 and 88, respectively.

With the brake 8| released and the brake 82 applied, the planet gears 16 will be held against bodily rotation sothat the drum 28 will be driven from the input shaft II. With the brake 8| applied and the brake 82 released, the ring gear 15 will be held against rotation so that the gypsy 2I will be driven from the input shaft II.

For the purpose of facilitating assembly, the input shaft I8 is made in two parts, the righthand part which carries the gear 43a and is journalled in the hub I8a of the drum I8, being hollow and receiving the adjacent end of the lefthand The valve 21 comprises a fixed part 85 provided rwith ports 86, 81, 88, 89, 98, EM and 92 which communicate, as designated by the lines 93, 94, 95, 96, 91, 98 and 99, respectively, with the cylinder 52, the lefthand end of the cylinder 66, the cylinder 12 and the righthand end of the cyl inder 66, the cylinder 69, the cylinder 83, the cylinder 84, and the cylinder 58, respectively.

The valve 21 has a rotary, conical, central part I88 provided with a cross passage I8I connected, as designated by the line air supply I83. The handle 26 is fixed to the part I88 for rotating the same.

An outer, annular part I85 is rotatable on the fixed part 85, and is connected by a pin I86a to the handle 26 for rotation therewith and with the I86 and. which register, respectively, with the 1,

ports 81, 88, 98 and 9|, when the valve is in position N. The valve part I85 is also provided with a port III which communicates with the exhaust passage I86 and which is extended and disposed as shown so that it opens the port 86 to only in the three positions handle 26. The valve part I85 is also provided with a port II2 which communicates with the exhaust passage I86 and which is extended and disposed as shown so that it opens the port 92 to exhaust only in the two positions C and D of the handle 26.

The inner end of the port 86 is extended as shown at' the adjacent surface of the central rotary part I88 so that the passage I8I communicates with this port only in the two positions C and D of the handle 26.

The inner end of the port 92 is extended as shown at the adjacent surface of the central rotary part I88, so that the passage I8I communicates with this port only in the three positions of the handle 26 designated as A, B and N.

Connected in the air line .93 leading from the port 86 of valve 21 is a valve H3, and connected in the air line 99 leading from the port 92 of the I82, with a compressedexhaust A, B and N of. the

IZII

, 2,179,082 3 valve 21 is a valve H4. The valves H3 and H4 are identical in construction and manner of operation, and have a common operating lever H disposed between them and connected to their rotary parts. The lever H5 is pulled down by a solenoid H5 when the latter is energized. The solenoid H9 is connected by lines H1 to the. .master controller 28, and the arrangement and connections are such that the solenoid is deenergized when the controller is in the-neutral position shown to shut off the motor, and is energized when the controller is moved to any one of the various steps on either side of the neutral position to cause the motor 25 to operate in one direction or the other, as will be well understood by those skilled in .the art. With the solenoid deenergized, a spring H8 is eifective to hold the lever H5 in the upper position shown, against a fixe'd stop H9. .Inthis position of the lever the valve H4 shuts off communication between the port 92 and the brake cylinder 50, and opens this cylinder to atmosphere through the exhaust port I20. When the solenoid is energized, the

lever H5 is pulled down to close off the exhaust port I20 and establish communication between the port 92 and the port I21 to the cylinder 50. In like manner, when the solenoid is deenergized,

the valve H3 shuts off communication between the port 85 and the brake cylinder 52, and opens this cylinder to atmosphere, and when the solenoid is energized the valve H3 closes the cylinder 52 to exhaust and establishes communication between this cylinder and the port 85 of the valve 21. I

With the valve 21 in any one of the three posi-.

tions A, B and N, the supply, of compressed air.

from the tank I03 will be open to the valve H4 by way of theline I02, the passage NH and the port 92. However, with the valve 21 in any one of the three positions A, B and N, the valve H3 will be open to exhaust in either position of the latter since the port 86 will, in each of the posicylinder 12 so that only the drum I1 will be tions A, B and N, be open to exhaust by way of port III and the exhaust passage I06. It W111 therefore be seen that with the valve 21 in anyone of the three po tions A, B and N, when the -master-controller 28 is moved to either side of theneutral position to energize the solenoid. I I6, compressed air will be permitted to pass through the valve H4 to the brake cylinder 50, but will not be permitted to pass through the valve II 3 to the brake cylinder 52., In any one of the three positions A, B and N of the-.valve 21, therefore, the brake band 48 will be released and the brake band 5I will remain applied so that only the input shaft I0 will be driven by the motor 25. through the planetary gearing 23 when the master controller 28 is moved to either side of its neutral position to energize the solenoid H6 and then start the motor.

f With the valve 21 in the position A to place driven from the input shaft III. With the va ve 21 in the position N to place the passage IOI in communication with the port 89, compressed'air will be supplied only to'the brake cylinder '89 so that only the drum I8 will be driven from the input shaft I0.

With the valve 21 in any one of the two positions 0 and D, the supply of compressed airfrom .the tank I03 will be open to the valve H3 by way of the line I02, the passage IOI and the port 86. However, with the valve 21 in any one of the two positions C and D, the valve H4 will be open to exhaust in either position of the latter since the port 92 will, in each of the positions C and D,.be open to the exhaust by way of port H2 and the exhaust passage I06. It will therefore be seen that with the valve 21 in any one of the two .positions C and D, when the master controller 28 is moved to either side of the neutral position toenergize the solenoid H6, compressed air will be permitted to pass through the valve H3 to the brake cylinder 52. In any one of the two positions 0 and D of the valve 21, therefore, the

brake band 48 will remain applied so that only the input shaft II will be driven by the motor 25 through the planetary gearing 23 when the master controller 28 is moved to either side of its neutral position to energize the solenoid I I6 and then start the motor. a

- With the valve 21 in the position C to place the passage IOI in communication with the port 90, compressed air will be supplied only to the brake cylinder 83 so that only the drum 20 will be driven from the input shaft II.

With the valve 21 inthe position D to place the passage H0 in communication with the port 9|, compressed air will be supplied only to the brake cylinder 84 so that only the gypsy 2I will be driven from the input shaft II.

From the foregoing, it will be seen that by means of the single valve 21, the drums and' gypsys can be quickly and easily selected foroperation individually, and that only one of theprovided at the opposite ends thereof with hollow stud shafts or hubs I23 and I24 journalled,

respectively, in bearings I25 and I26. An input shaft I21 is journalled in a bearing I28 and in the hub I23 and a partition or central'wall I29 of the drum I22.

A second drum I30 is mounted on and has it opposite hubs I3I and I32 keyed to a hollow output shaft I33-which is journalled in the hub I24 of the drum I22. The hub I32 of the drum I30 is journalled in a bearing I34.

The input shaft I21 is driven by a motor I35 through a chain I35 connecting a pinion I31 fixed on the motor armature shaft with the sprocket I38 disposed between the bearings I28and I25.

The drums I 22 and I30 are driven, selectively, from the input shaft I21 through planetary gearing comprising a sun gear I39 fixed on the shaft I21, a ring gear I40 fixed on the inside of the drum I22, and planet gears I carried by a spider 2 which, on one side, is fixed with re-' spect to the hollow output shaft. I33 and, on its other side, is journalled on the input shaft I 21;

. Fixed with respect to the drum I30 is a brake drum. I43 about which is a friction brake band I44. The operating gear or mechanism for the brake band I44 is of a conventional construction,

as represented in Fig. ,9. That is,upon the admission of; compressed ,air to a cylinder I45, the band I44 is released against the action of a spring I46,.and when the compressed air to the- The reference numeral I22 designates a drum cylinder is shut off and the latter exhausted or vented to atmosphere, the spring I46 becomes effective to apply the brake band I44 and hold the drum against rotation and the planet gears I4I against bodily rotation about the common axis of the shafts I21 and I33.

Fixed with respect to the drum I22 is a brake drum I41 about which is a friction brake band I48, the operating gear or mechanism for the latter being similar to that for the brake band I44. That is, upon the admission of compressed air to a cylinder represented at I50 and which corresponds to the cylinder I45, the band I48 is released against the action of aspring similar to and operating in the same manner as the spring I46. When the compressed air to the cylinder I50 is shut off and the latter exhausted or vented to atmosphere, the spring referred to becomes effective to apply the brake band I48 and hold the drum I22 and the ring gear I40 against rotation.

The unit just described might be compared to that part of the winch shown in Figs. 1 and and comprising the drum 20 and the gypsy 2|.

- That is, the gear I38, the input shaft I21, the

hollow output shaft I33, the drum I22, the drum I30, the bearing I 26, the brake cylinders I50 and I45 in Fig. 8 correspond, respectively, to the gear 46, the input shaft II, the hollow output shaft 18, the drum 20, the gypsy 2I, the bearing I5, and the brake cylinders 83 and 84 in Figs. 1 and 5.

With the input shaft I21 rotating, upon the admission of compressed air to the cylinder I50 to release only the brake band I48, the drum I22 will operate since the brake band I44 remains applied to hold the drum I30 against rotation and the planet gears I4I against bodily rotation about the common axis of the shafts I21 and I33. Upon the admission of compressed air to the cylinder I45 to release only the brake band I44, the drum I30 will operate since the brake band I48 re mains applied to hold the drum I22 and the ring gear I40 against rotation.

Selection of the drums I22 and I30 is made by operation of a single valve I 5| similar in construction and manner of operation to the valve 21 in Figs. 1 and 2. That is, with the valve in the neutral position shown, the cylinder I45 is open to atmosphere through the pipe connection represented by the line I52, the port I53 in the fixed part I54, and the exhaust passages I55 and I56 in the rotary part I51 which is connected to the rotary part I58 for rotation therewith. Also. with the valve in the neutral position shown, the

cylinder I50 is open to atmosphere through the pipe connection represented by the line I58, the port I59 in the fixed part I54, and the exhaust passages I60 and I56 in the rotary part I51. The rotary part I51 is provided with a passage I6I to which compressed air is supplied by a connection represented'by the line I62.

From the construction just described, it will be seen that upon rotation of the valve parts I51 and I56 to the position E, compressed air will be supplied to the cylinder I50 to release the brake band I48, and that upon rotation of the valve parts I 51 and I58 to the position F, compressed air will be supplied to the cylinder I 45 to release the brake band I44.

In the neutral position of the valve I5I, a switch I63, connectedas shown in the motor supply circuit, is open, butin either of the operating positions E and F of the valve, the switch I63 is closed. For this p rp se, the arm of the switch may be connected for rotation with the rotary valve part I58 by a shaft represented by the line I64.

The motor I35 is provided with a brake I65 of a conventional construction, and which is released upon the-supply of compressed air to the cylinder I66, under control of a valve which is opened upon excitation of a solenoid I61 connected in the motor circuit.

In operation, the valve I5I is moved to either of the two operating positions E and F, depending upon which of the two drums I22 and I30 is to operate, after which the motor controller I68 is moved to either side of the neutral position in which itis shown to release the brake I65 and cause the motor to operate in the desired direction and at the desired rate.

The switch I63 provides a safety feature whereby the motor can not be started unless the valve I H is in one of its two operating positions to release either the brake I48 or the brake I44.

If the drum I30 is not required, this is omitted, as well as the associated bearing I34. In such case, also, the output shaft I33 is shortened to extend only a short distance beyond the bearing I26, and is permanently fixed against rotation in any suitable manner so that theplanet gears I4! are always fixed against bodily rotation about the common axis of the shafts I21 and I33. The valve I5I, also, is simplified so that it has only the one operating position E.

The term drum in the claims is used in the broader sense,'and is intended to refer also to a p y- It will be understood that various modifications of the disclosed embodiments of my invention are possible without departing from the spirit of my invention or the scope of the claims.

I claimas my invention:

1. In a winch, input shafts supported for rotation independently of each other, drums driven respectively from said shafts, a single power shaft common with respect to said input shafts,

means for selectively connecting said input from one of said shafts, a drum driven from another of said shafts, a single power shaft common with respect to said input shafts, means including planetary gearing for selectively driving from said one of said input shafts the re V spective drums associated therewith, and means,

for selectively connecting said input shafts to said power shaft for operation therefrom.

3. In a winch, input shafts supported for rotation independently of each other, drums driven from one of said shafts, drums driven from another of said shafts, a single power shaft comfrom said power shaft, planet gears for driving shafts" drums driven from another of said shafts; respectively from said shafts, a single power shaft individually.

, tion independently of each other, drums drivm means for selectively connecting said input shafts to said power shaft for operation therefrom.

4. In a winch, input'shafts supported for rotation independently of each other, drums driven from one of said shafts; drums driven from an from one of said shafts, drums driven from another of said shafts, means for selectively driving from said one of said input shafts the respective drums associated therewith, means for selectively driving from said another of said input shafts the respective drums associated therewith, power jspective drums associated therewith, means inother of said shafts, a single power shaft om means for selectively driving said input shafts, mon with respect to said input shafts, means fluid-pressure means for controlling said firstincluding planetary gearing .for selectively drivnamed means and said second-named means and ing from said one of said input shafts the r said power means to select said drums for opera-v spective drums associated therewith,- m an 1 1- .tion individually, and a single valve for concluding second planetary gearing for selectively trolling .Said fluid-pressure means.

driving from said another of said input shafts 9. In a winch, input shafts supported for rotathe respective drums associated therewith, means i9 independently of each other, drums driven for selectively connecting said input shafts to from n o s d s a s. drums'driven from an said power shaft for operation therefrom; said I other of said shafts, means including. friction third-named means inomding thir lan ta brakes for selectively. driving from said one of gearing comprising a sun gear driv n directly said input shafts the respective drums associated said one of said input hafts a d ri gear selectively driving from said another of said input for driving said another of said input shafts; shafts the respective drums associatedtherewith, and means for selectively holding id ring gear power means including friction brakes for selecagainst rotation and said planet gears against tively drivin sa input ffl -p e ure' bodily rotation about the axis of rotation of said means for tr llin said brakes to select said sun gear, a drums for operation individuallin'and-a single 5 In a winch, input, shafts supported f valve for controlling said fluid-pressure means.

tation independently of each other and about 10. In a winch, input shafts supported for roa common axis, drums driven from one of said tation independently of eachother, drums driven 1 1 power shaft common with respect common with respect to said input shafts, means said n t shafts and supported g rotation including planetary gearing for selectively conabout an axis substantially parallel to the com-, ting said input shaf s to s P r shaft n axis ofrotation m input, shafts means operation therefrom, brake drums associated with including planetary gearing fbr selectively m said planetary gearing, friction brake bands asing from said Qne of said input h ft sociatedrespectively with said brake drums, each of said bands being provided with spring means cluding second planetary gearing for selectively 1 applying the same n fluid-Pressure cylintherewith, means including friction brakes for ng from said anqther of said input hafts ders for controlling therespective bands and each therespective drums associated therewith, and means for selectively connecting'said input .shafts to said power shaft for operation therefrom.

6. In a which, input shafts supported for rotation independentlyof each other, drums'driven from one of said shafts, drums driven from an-. other of said shafts, means for selectively drtving from said one of said input shafts the respective drums associated therewith, means for selectively driving from said another of said input shafts the respective drums associated. therewith, power means for selectively driving said input shafts, and single means common with respect to all of arranged to release the associated band when under fluid pressure and when vented to permit such band to be spring-applied thereby to hold the associated drum against rotation.

11. In a winch, a power shaft, a first drum and a second drum and-a third drum supported for rotation about-a. common axis, planetary gearing disposed in said third drum and providing a driving connection between said shaft and'said drums, means for causing said drums to be driven individually and selectively from said shaft through said planetary gearing, said means including. a clutch element associatedwith said first andsecond drums and movable in a direc- 'for' selectively'driving said input shafts, and-'sin-' said drums and to said. input shafts and to saidsubstantially Parallel said we power means for controlling Basement either of Said first and Second means and-said second-name means and said In t: and means controlling 8814 wer means to sel drums 11am m l p0 eat Sam f 12. In a'winch, drumssupported for rotation, '7. In a winch, input shafts supported for rotain input shaft planets gearing u in tion independently of each other, drums driven "driving between 5 shaft and said from one of said shafts, drums driven from anmeans for 9 n: 5am drums to g ogleroksaidl shafts, means including friction individually and selectively from said shaft brakes ts selectively driving from said one through said Planetary t said means sam input shaftstthejrespeguvedm MM "eluding a clutch element associated with certain therewith, means including friction brakes 'for selectively driving from said another of said input shafts therespective associated therewith, power means'including friction brakes certain 01 881d drums, Md fl -9W mm for controlling said first-named meansand ingle means common with respect to all of said l n 8111816 V v m v 1M lfl' rent 0P- brakes for controlling the same to select said crating positions I ,for the respective drums for operation.individually.f Y drums for rotation by said shaft through said 8. In a winch, input shafts planetary gearing. r

' MELVIN B. BENSON.

stantially' parallel to the axis of rotation of the for rotaof said drums and movable in a direction sublatter into either 'oftwo oper ting positions with 

